Methods, systems and/or arrangements falling, within the above technical field and the above mentioned natures are previously known in a plurality of different forms and/or embodiments.
By way of introduction here, the Scanning Probe Microscopy (SPM) has been used for the development within the nano-science area. The use of resonance frequentcy shifts of oscillating movement for imaging (non-contact mode) has made it possible to image true atomic resolution.
Since mid 1990s cantilevers have been utilized, not only for forced transducers in SPM but also for sensing applications, whereby various kinds of interactions with and on a cantilever surface have been translated or transformed into a mechanical motion.
The principle behind how cantilevers may transduce and interpret events on its surface thereof relates to either a mass changing, depending upon mass absorption of a resonating system or on a surface stress, causing the cantilever beam to bend.
By this it has been able and possible to measure various properties with higher sensitivity than conventional methods.
Examples are exothermic and/or endothermic reactions, i.e. heat, mass changes, surface stress, molecular interactions, detection of vapors, protein interactions, DNA and recently antigen-antibody reactions.
These properties have been studied in various kinds of environments, such as in air, in vacuum and within a liquid.
Typically, the cantilevers being exploited or used in these areas, have been allotted dimensions in the micrometer (10−6) scale or area, their selected lengths are in the range of 100 s of micrometers, widths of roughly 100 micrometers (μm) and thicknesses around 500 nm (10−9).
Typically, for such cantilevers, a surface stress of 10−3 N/m causes a bending of around 10 nm; a change of 1 Hz between measured resonance frequencies corresponds to a mass increase of 10−6 g, and/or a temperature change of 10−5 K, causing a deflection of some nanometers.
Such values are straight forward to measure, often based on optical deflection technology, utilizing the reflection of a focused laser light spot, onto a position within a light sensitive detector.
Thus, bearing in mind that the resolution limits in SPM-systems are around or better than 1 Å or so, it has been possible to obtain sensitivities for mass changes of ≈ag, heat of 1 J, surface stress of 0.1 μN|m.
Further prior art publications are to be found in the “Reference List” attached to this description as its last page.
The present invention thus is a further development of an arrangement for detection of a first resonance frequency, related to a mass weight loaded carrier means, and to compare said first resonance frequency with a second resonance frequency, serving as a reference frequency, related to said carrier means alone, without said mass weight, by using a frequency comparing and/or calculating means to evaluate, by a noted frequency shift, for the loaded mass a significant mass weight as illustrated in the preamble of claim 1.